Display devices are evolving in various ways to meet consumer needs. As one example, recently being developed are transparent display devices which provide a display function while allowing a person to see through the display as if seeing through glass. Since a transparent display device is based on a see-through display, the person, being located in the rear surface of the transparent display device, can still see objects or a scene occluded by the transparent display device.
For example, a transparent display device can be implemented as described below. In case a transparent display device is installed as a show window of a shop, people can see the products of the shop through the transparent display device but also see the information of the products displayed on the transparent display device. Similarly, in case a transparent display device is implemented in the form of a digital signage which displays digital information, people can see various kinds of digital information displayed on the transparent display device while still being able to see objects or a scene through the transparent display device.
In particular, in the case of the example above, if a transparent display device can be controlled by the person's gaze directed toward the transparent display device, utilization of the transparent display device can be greatly enhanced.